zadok

...dont forget to breathe thru that straw u r clutching....

You're trying to compare two coins that appeal to two largely different groups of collectors, those who try to obtain coins with the highest awarded numerical grades for their registry sets and those who collect mint errors. (The NGC Registry doesn't even allow coins attributed as mint errors.)  The NGC Price Guide has no price for a MS 68 graded 1976 clad Bicentennial quarter, while the PCGS Price Guide lists it at $4,500. Each error coin is essentially unique and commands its own price, so you can't compare this particular coin with the certified populations of pieces graded "MS 68."
   You could check auction records for each of these coins and determine what each has actually realized at any public sale.  Which one is "more rare and valuable" is inherently a matter for conjecture.

...hoards n accumulations a collection they do not make....

...true plus a few others that were privately distributed, contrary to what one so-called "expert" espouses here n elsewhere....

...could u differentiate tween ape-poopy n monkey-s..t?....

He was not real. It happens on the forum all the time.  AI has the capability to do all sorts of stuff HC and why bring this up again. It just takes up Time + Space.

But ya gotta be careful and check the plumbing. 

...cept for surfer girls....

...absolutlely correct...pedigree sells, hence all the "ex-*****" on labels n auction descriptions...fortunately some of the repetitively, nauseatedly referenced ones on this forum will never be ex-anything....

...rest assured there was a comprehensive inventory compiled of all the coins in the accumulation referred to as the"Fairmont" coins, im certain the owner(s) have full accountability...as u suspect, not all of the assembled coins were worthy of certification n it is reasonable to speculate that many have been sold off in other markets with certain provisions...if long term u desire a complete inventory of contents im not sure that will ever be available, but as mentioned before those coins sold under the "Fairmont" labeled name should be retrievable...if u want a bit more data on the origination source(s) of this grouping of coins, PM me n i will discuss further....

...u seek too much...as we have discussed many times, the dispersal of this accumulation is by design...the pural of hoards is hoard...the distribution by dates, mints, grades n denominations will be retrievable eventually...where the coins came from originally (read multi-source) is not relevant ....

...44 months...id say crawling rather than running....

Here are some hard to find 1901 Pan-Am award medals in my collection. They are all R-5 and there are 41 sterling silver known, 31 Gilt bronze known and 32 Bronze known. They are seldom seen and I think they are beautiful. Herman McNeil the designer of the standing liberty quarter designed them for the 1901 Pan-American expo in Buffalo N.Y.

See the linked page, which indicates that such an impaired coin would be graded "Uncirculated Details".

Here is your "credible explanation":
  See What is an Adjectival Grade? | NGC (ngccoin.com), where NGC explains, "For some bulk submissions, NGC will allow the submitter to request that only the adjectival grade be printed on the NGC certification label. This is generally done only for large submissions of relatively common coins. The coins must still meet NGC’s requirements for the numeric grade range for that adjectival grade. . ..  UNCIRCULATED is often paired with the additional qualifiers of BRILLIANT, CHOICE, or GEM. NGC considers BRILLIANT UNCIRCULATED to be any coins that would grade from 60-70 on the Sheldon Grading Scale. CHOICE UNCIRCULATED is considered to be any coins that would grade from 63 to 70. GEM UNCIRCULATED (sometimes indicated as GEM UNC or GEM BU) is used for coins that would grade from 65 to 70."
   Presumably, a bulk submission coin graded "UNCIRCULATED" would be a lower end mint state coin that would have been graded no higher than MS 62 if submitted for numerical grading. I understand that it would be scored as a "MS 60" in the NGC Registry.
   NGC has been offering this service for bulk submitters for some time. It is not uncommon to see Morgan and Peace dollars and modern issues in NGC holders with these adjectival grades.

...absolutely agree....

That is a lot of coins, good luck with the auction.
While you are correct that the marketplace section is the right place, I find this to be far more interesting than the usual parking lot "what error is this" threads or the babble of QA's threads.

...i would not consider this coin impaired, there is minimal if any verdigris n questionable if there is staining versus toning, whether it has been cleaned n re-toned is the question n not determinable from photographs/lighting...the coin if straight grades, XF45 n possibly AU50 unless determined to have been cleaned...50/50 on that, the toning pattern a bit iffy....

...u can put it on ur epitaph....

...or as just mentioned foreign matter that spread n finally came off the die, makes sense since u found examples in later die state without the depressions....

...astute observations...im sure others have seen the depression(s) n wondered similar thoughts n most assumed it was a random occurrence, obviously not random after ur research, almost has to have been a die defect of some type that continued eroding??....

...QA in one of his more lucid moments....

Could be MB-269.
Ok, below is a link to the CNS book where you can download a .pdf.
https://www.academia.edu/26698446/Vladimír_Hanibal_Emil_Novák_Malé_groše_Small_Groschen_Kleine_Groschen
The MB#'s are from Krause (The Standard Catalog of World Coins) and stand for Mishler-Bruce who were the catalogers of such pieces, I believe one or both had worked at Krause. At one point Krause was back-building catalogs, first to 1701 then to 1601-1700, but never completed a Standard Catalog for 1501-1600 even though a substantial amount of cataloging had been done. The MB#'s seem to mostly consist of coins who's existence predates 1601 and which were included in the last edition of the SCWC 1601-1700 as work was stopped on the 1501-1600 catalog. Not really helpful to your cause but I found it interesting and thought I'd post it for others to see. There is a viewable copy of the SCWC 1601-1700 which includes MB#'s, you can find it HERE. 
Krause is good, Numista is better but you have to take all of the information with a grain of salt, both are imperfect and neither contain all available info for every coin.I also just noticed that there is a notation for some of the MB#'s stating "Varieties Exist", if you really want to dive deep into these you're going to have to find more specialized references and don't be surprised if most and/or the best are in another language but I think you're close with the MB-269 so you might not have to delve too much more deeply. Good luck.